Bale strap means and pulp bale combination



July 11, 1967 M. B. JORGENSEN BALE STRAP MEANS AND PULP BALE COMBINATION2 Sheets-Sheet 1 Filed Aug. 3, 1964 FIG. 4

FIG?) United States Patent 3,330,409 BALE STRAP MEANS l) PULP BALEC(BMBENATION Mark B. Eorgensen, Neenah, Wis, assignor to Kimberly-Clarir Corporation, Neenah, Wis., a corporation of Delaware Filed Aug.3, 1964, Ser. No. 386,885 2 Claims. (Cl. 206--83.5)

My present invention relates to the baling of pulp and is particularlyconcerned with the provision of novel pulp bale strap means forretaining pulp securely in baled form during shipment and storage.

Wood pulp is commonly baled by pulp producing mills for the purposes ofboth storage and shipment. The pulp, when baled, normally contains aquantity of water, at least about 5 to by weight. This water content maychange during storage or shipment depending upon atmospheric conditions.Change of moisture content exerts a varying degree of stress by the baleupon the usual metallic baling strapping.

The metallic baling strapping generally used commercially in pulp balingis in the form of quite narrow widths of flexible steel or the like andmay be identified as the type of strapping used as the strapping onlarge cardboard cartons. Such metallic strapping is costly in pulpbaling procedures, both from the point of View of the strapping itselfand from the point of view of handling. The metallic strap isparticularly disadvantageous in that it must be removed before the pulpbale is fed to the equipment containing the aqueous medium in which thepulp is redispersed. Upon removal, the metallic strapping may have someslight value as scrap metal but the handling and storage costs do notmake this procedure economically attractive. Also, in handling suchmetallic strapping the possibility of injury is present because of thespringiness and resiliency of the strapping.

By my present invention the necessity for metallic strapping, and itsconsequent disadvantages, is eliminated. I have found that dry sheetpulp in the form of relatively narrow bands may be made endless andemployed as the sole retention means for bales of cellulosic pulp. Byrelatively narrow bands I mean bands which are narrow in relation to thedimensions of the pulp bales. For the purposes of attaining adequatestrength in the relatively narrow bands, the pulp material forming thebands should preferably be of long fibered pressed pulp material.

Importantly, the pulp material which forms the strength member is itselfwater dispersible. Also the pulp material need not itself be speciallymade for the purpose; narrow widths may be skived from regular pulpsheet production in substantially continuous lengths for use as thestrapping material. While kraft pulp is preferred, any strong pressedpulp sheet having strength characteristics similar to kraft may beemployed. Water dispersibility provides that the bale itself, includingthe bale strap, may, upon usage, be fed directly to the tanks in whichpulp dispersion is to take place. In a preferred embodiment of theinvention the bale strapping material is made endless with a waterdispersible adhesive; the adhesive may be selected to be compatible withconditions of the process for which the pulp, when dispersed, isintended. Alternatively, the bale strapping material may be made endlesswith staples, synthetic glues, mechanical devices or the like-and beforeuse the joint may simply be snipped from the main body of the balestrapping means and discarded or directed to other purposes. It is to beparticularly noted that the bale strapping material is made endless atthe time of application of the strap material to the bale in the samemanner as conventional metallic strapping is applied.

It is, accordingly, an object of my present invention to provide a pulpbale strapping which is readily handled, is economical, is of the samegeneral nature as the material which it bales, may be subjected to thesame pulp dispersion processes and utilized as a component of the sameend product for which the baled pulp is intended-and which requiresessentially no separate handling by a user of the baled pulp.

These and other allied objects of the invention will be apparent fromthe following detailed deescription and accompanying drawings wherein:

FIG. 1 is a perspective view of a pulp bale retained by a pair of balestraps formed in accordance with the invention;

FIG. 2 is a view of a strap in completed form but in which form it wouldnormally be made endless and complete in a circumferential sense aboutthe bale;

FIG. 3 is an enlarged and fragmentary view illustrating the corrugatednature of the surface of a preferred embodiment of strapping material;

FIG. 4 is an enlarged and fragmentary edge view illustrating a strapjoint;

FIG. 5 is a fragmentary view in plan of another embodiment of the strapof invention;

FIG. 6 is a view taken on line 6-6 of FIG. 5;

FIG. 7 is a view of yet another embodiment of a joint useful inconjunction with the bale strap of the invention and which includesstaples;

FIG. 8 is a fragmentary View of a further embodiment in which the strapon the bale is provided with an additional protection againstcontamination with liquid; and

FIG. 9 is a view of a further embodiment of the strap joint in which thejoint includes punched openings.

Referring to the drawings, the numeral 1 designates the ordinary pulpbale which may have the following dimensions: 28 inches by 32 inches by16 inches. The bale is formed, pressed under high pressure, and thenallowed to relax somewhat before strapping.

The bale is retained by the bale straps designated at 2; the strapmaterial is made endless about the bale by joints as at 3. As shown moreclearly in FIGS. 2 and 4, the joints of the structure of FIG. 1 maysimply include an adhesive 4. The adhesive 4 is preferably waterdispersible; one such glue is animal glue which penetrates pulp stockwell.

The surfaces of the strap material, as shown at 5 in FIG. 3, ispreferably corrugated. These corrugations assist in retention of theglue or adhesive 4 and materially assist the formation of a strongjoint. These corrugations normally occur in the production of the sheetpulp material in procedures employing the well known Kamyr press; theyare not essential to the practice of the invention but provide for someinterlocking at the joint. When the corrugations or the like are notnormally present in the pulp material as formed, the surfaces may beroughened if necessary to aid the strong joint formation.

As shown in FIG. 5, the joint may be formed by sections of strapmaterial of diiferent widths. For this purpose one end of a singlelength may be skived down; or pieces of differing widths may beemployed, in which case the complete bale strap has two or more joints.Such arrangements afford, by virtue of the provision of a Wide slot 7through the thickness of the wide material 6, a better gripping capacityfor the end of strap 8 which, as is shown, is serrated at 9. Theserrated end passes through slot 7 and overlies material 6. As indicatedin FIG. 6, when such arrangement is employed, glue is utilized to retainthe serrated portion in intimate contact with the lower strap portion;the serrations inhibit withdrawal through the slot.

As shown in FIG. 9 the glued joint may be further strengthened at thejoint by simply punching the superposed straps 2 completely through, asindicated at 1 1,

such that the pulp material is peened over as at 12. An-

use. As shown in FIG. 8, a bale may be suitably provided at its lowerend with an overlying protective water resistant film strip ofpolyethylene, for example, glued to the strap and bale body with thesame material as the glue of the strap joint. This protective materialserves the purpose of preventing intimate contact of the strap withwater or the like on the floor of a freight car, for example. Commonly,such strip is unnecessary, however.

In practice I have found that the strap material may be formedinsubstantially endless lengths by skiving an appropriate width ofmaterial from pressed pulp sheets as they are formed. The sheetmaterial, preferably for the baling purpose, is conveniently solely ofsoftwood (coniferous) kraft long fibered pulp; southern pine, spruce andthe like serve the purpose well. The kraft (sulfate) pulp is commonlyofgreater strength than sulfite pulp, particularly hardwood sulfite pulpsand, accordingly, a greater width and thickness is usually necessary toattain the same strength property with the latter material. Some sulfitepulps tear readily and are, accordingly, not recommended for thepurpose. The strap ing material may be and usually is bleached in thenormal course of production, and no special precaution need be taken inthis respect with respect to strength factors. The strap width for thetypical bale dimensions mentioned hereinbefore may be less than fourinches. The optimum width for particular conditions to which the balestrapping may be subjected varies somewhatwater pickup by the strapmaterial tends to weaken the strapywhen the conditions for water pickupare not present to any material extent, strap widths as low as about oneinch have been found suitable with the bale dimensions mentioned andutilizing kraft (sulfate) hard pressed dry pulp. The strap material,while normally relatively inextensible and demonstrating more thansuflicient strength in thin thicknesses of about to A inches, willextend somewhat with moisture pickup; the bale of pulp, of course, alsotends to extend in dimension under the same moisture conditions.Accordingly, stress caused by bale expansion tends to be relieved bystrap extension due to the moisture pickup. More specifically, the straptends to expand and contract with the bale. However, complete wetting ofthe strap is to be avoided and, if water dispersible adhesives areemployed, the joint should, of course, be well up on the bale and awayfrom contact with sources of liquid water. The extent of the overlap atthe joint is usually between about 2" to 3" with the adhesives and jointform- 'ing means I have employed the pulp redispersion process. Thewater soluble or water ing production. A 50% solids content of animal.glue in water serves the purpose well. If heated to about 140, suchadhesive penetrates quickly and dries to a hard set condition in lessthan four minutes. The strap material, however, is characterized by ahigh degree of flexibility and may be bent quite sharply without seriousfracture through its thickness and, accordingly, conforms well to theshape of the baled pulp. Other adhesives which I have found usefulinclude synthetic rubber (neoprene) polyvinyl acetate solutions intoluene having a solids content of about 21.523% and a viscosity ofabout 800 to 1300 centipoises. Adhesives produced by the Borden ChemicalCompany Arabol Division under the trademark SN-905 are of the lattertype and serve the purpose. The V adhesive, however, as long as it iscapable ofproviding sufiicient bond strength, is not critical as thejoint may be snipped from the strapping and the remainder of the pulp ofthe strap employed in conventional pulp'processes, for the remainder ofthe strapping requires no treatment whatsoever to make it acceptable forthe purpose.

In application to the pressed bale of pulp the strapping is simply drawnabout the bale under tension and secured mechanically or by adhesive.With some adhesives a holding time of about 10 minutes may be requiredto permit the adhesive to set-such holding time characterizes thesynthetic rubber base adhesives which I have employed. Pressure may beemployed in conventional manner to assist adhesive setting.

In practice the pressed pulp has proved useful for its intended purposeand to withstand handling in shipment in a thoroughly satisfactorymanner.

' It will be understood that this invention is susceptible tomodification in order to adapt to different usages and conditions and,accordingly, it is desired to comprehend such modifications within theinvention as may fall within the scope of the appended claims.

What is claimed is:

1. In combination, a pulp bale and bale strap means made endless in acircumferential sense about the bale retaining the pulp bale, said balestrap means being in the form of relatively narrow band means of longfibered softwood pulp, the pulp of said bale and of said band meansbeing of the same general characteristics such that the band means hasessentially the same utility for pulp processing as does the pulp of thebale.

2. The combination as claimed in claim 1 and in which the bale strapmeans includes at least one joint whereby the bale strap means is madeendless and said joint com- References Cited UNITED STATES PATENTS981,890 1/1911 Smith. 1,779,335 10/1930 Remrey 206. X 2,004,098 6/ 1935Andrews 20665 2,271,632 2/ 1942 Diehl. 3,089,634 5/1963 'Heise et al.209-49 3,235,071 2/1966 Simich et al 20683.5

LOUIS G. MANCENE, Primary Examiner,

1. IN COMBINATION, A PULP BALE AND BALE STRAP MEANS MADE ENDLESS IN ACIRCUMFERENTIAL SENSE ABOUT THE BALE RETAINING THE PULP BALE, SAID BALESTRAP MEANS BEING IN THE FORM OF RELATIVELY NARROW BAND MEANS OF LONGFIBERED SOFTWOOD PULP, THE PULP OF SAID BALE AND OF SAID BAND MEANSBEING OF THE SAME GENERAL CHARACTERISTICS SUCH THAT THE BAND MEANS HASESSENTIALLY THE SAME UTILITY FOR PULP PROCESSING AS DOES THE PULP OF THEBALE.